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WO2014192889A1 - Dispositif et procédé de reconstruction d'image à différentes énergies de rayons x, et dispositif et procédé de mesure tridimensionnelle aux rayons x - Google Patents

Dispositif et procédé de reconstruction d'image à différentes énergies de rayons x, et dispositif et procédé de mesure tridimensionnelle aux rayons x Download PDF

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Publication number
WO2014192889A1
WO2014192889A1 PCT/JP2014/064330 JP2014064330W WO2014192889A1 WO 2014192889 A1 WO2014192889 A1 WO 2014192889A1 JP 2014064330 W JP2014064330 W JP 2014064330W WO 2014192889 A1 WO2014192889 A1 WO 2014192889A1
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Prior art keywords
ray
image
dimensional
measurement
reconstruction
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PCT/JP2014/064330
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English (en)
Japanese (ja)
Inventor
亮 紋川
中西　正一
阿部　真也
幹也 近藤
晃 原田
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地方独立行政法人東京都立産業技術研究センター
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Priority to EP14804436.5A priority Critical patent/EP3006924B1/fr
Priority to JP2015519944A priority patent/JP6280544B2/ja
Priority to US14/894,325 priority patent/US9928619B2/en
Priority to EP16180850.6A priority patent/EP3109625B1/fr
Publication of WO2014192889A1 publication Critical patent/WO2014192889A1/fr
Priority to US15/674,396 priority patent/US10521936B2/en

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N23/00—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00
    • G01N23/02—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material
    • G01N23/04—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material and forming images of the material
    • G01N23/046—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material and forming images of the material using tomography, e.g. computed tomography [CT]
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B15/00—Measuring arrangements characterised by the use of electromagnetic waves or particle radiation, e.g. by the use of microwaves, X-rays, gamma rays or electrons
    • G01B15/04—Measuring arrangements characterised by the use of electromagnetic waves or particle radiation, e.g. by the use of microwaves, X-rays, gamma rays or electrons for measuring contours or curvatures
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T11/00—2D [Two Dimensional] image generation
    • G06T11/003—Reconstruction from projections, e.g. tomography
    • G06T11/008—Specific post-processing after tomographic reconstruction, e.g. voxelisation, metal artifact correction
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T7/00—Image analysis
    • G06T7/0002—Inspection of images, e.g. flaw detection
    • G06T7/0004—Industrial image inspection
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N13/00—Stereoscopic video systems; Multi-view video systems; Details thereof
    • H04N13/10—Processing, recording or transmission of stereoscopic or multi-view image signals
    • H04N13/106—Processing image signals
    • H04N13/156—Mixing image signals
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N13/00—Stereoscopic video systems; Multi-view video systems; Details thereof
    • H04N13/20—Image signal generators
    • H04N13/204—Image signal generators using stereoscopic image cameras
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
    • H04N23/60—Control of cameras or camera modules
    • H04N23/63—Control of cameras or camera modules by using electronic viewfinders
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2223/00—Investigating materials by wave or particle radiation
    • G01N2223/07—Investigating materials by wave or particle radiation secondary emission
    • G01N2223/076—X-ray fluorescence
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2223/00—Investigating materials by wave or particle radiation
    • G01N2223/40—Imaging
    • G01N2223/408—Imaging display on monitor
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2223/00—Investigating materials by wave or particle radiation
    • G01N2223/40—Imaging
    • G01N2223/423—Imaging multispectral imaging-multiple energy imaging
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T2207/00—Indexing scheme for image analysis or image enhancement
    • G06T2207/10—Image acquisition modality
    • G06T2207/10072—Tomographic images
    • G06T2207/10081—Computed x-ray tomography [CT]
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T2207/00—Indexing scheme for image analysis or image enhancement
    • G06T2207/10—Image acquisition modality
    • G06T2207/10116—X-ray image
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T2207/00—Indexing scheme for image analysis or image enhancement
    • G06T2207/30—Subject of image; Context of image processing
    • G06T2207/30108—Industrial image inspection

Definitions

  • the present invention relates to an X-ray energy-specific image reconstruction apparatus and method, and an X-ray three-dimensional measurement apparatus and method.
  • the X-ray CT apparatus can obtain a three-dimensional image including the internal structure of the object by reconstructing an image obtained by photographing the object with X-rays from various directions.
  • this X-ray CT apparatus has been used for observation of minute internal defects such as voids and cracks in metal parts and resin parts, measurement of complicated internal shapes of electronic parts, and analysis of failure causes. (See Patent Documents 1 to 4).
  • the digital engineering system is a technology that realizes efficiency and quality improvement from development to manufacturing by fusing a high-performance CAD / CAM system, a three-dimensional modeling system, and a three-dimensional measurement system.
  • ⁇ Digitizers and optical cutting methods have been proposed as 3D measurement systems.
  • these methods can accurately measure the surface shape, it is extremely difficult to measure the internal shape of the measurement object.
  • an ultrasonic diagnostic method capable of determining the presence or absence of an internal space has been proposed, but it is difficult to accurately grasp the internal shape of this method as well. Therefore, the X-ray CT apparatus is expected as the only three-dimensional measurement system that can grasp the internal structure.
  • CT images When using an X-ray CT apparatus as a three-dimensional measurement system, how to improve the measurement accuracy of CT data is the key.
  • Artifact generation conditions include, for example, a large difference in absorptance such that metal is scattered in the resin, and a case where the X-ray passage distance varies greatly depending on the imaging direction.
  • Equation (1) is valid in the case of imaging with monochromatic X-rays, but in the case of continuous X-rays used in actual measurement, the mass attenuation coefficient changes depending on the energy of the incident X-rays, so it does not hold.
  • the transmitted X-ray intensity I is
  • a conventional X-ray CT apparatus for three-dimensional measurement can maintain a certain dimensional accuracy when using a specific measurement standard (calibration jig), but in measurement using an actual measurement object. It is known that dimensional accuracy cannot be maintained. The reason for this is that the resolution of the X-ray detector is lower than the actual measurement accuracy, and the shape and material of the actual measurement object are various. For this reason, development of the technique for correct
  • the present invention relates to an X-ray energy-specific image reconstruction apparatus and method, an X-ray three-dimensional measurement apparatus, and an image reconstruction apparatus capable of realizing higher-accuracy image reconstruction by correcting artifacts and the like that have been problems in the past. It aims to provide a method.
  • the present invention provides, for example, an X-ray source that irradiates an imaging target sample with X-rays, an energy dispersive detector that detects characteristic X-rays generated from the imaging target sample, and the detector
  • An image reconstruction device for each X-ray energy comprising: signal processing means for digitizing a peak of characteristic X-rays detected in step (1); and image reconstruction means for reconstructing an image based on a signal from the signal processing means.
  • the present invention irradiates a sample to be imaged with X-rays, detects characteristic X-rays generated from the sample to be imaged with an energy dispersive detector, quantifies the peak of the detected characteristic X-ray,
  • an X-ray energy-specific image reconstruction method for reconstructing an image based on peak numerical data.
  • the present invention provides an image acquisition means for acquiring an X-ray CT image of a measurement object on a three-dimensional coordinate axis, an actual measurement means for actually measuring the three-dimensional shape of the measurement object on the three-dimensional coordinate axis, and an image acquisition means.
  • Image correction means for correcting the X-ray CT image so that the sinogram of the acquired X-ray CT image of the measurement object is converged to the sinogram of the three-dimensional shape of the measurement object actually measured by the actual measurement means;
  • An original measuring device is provided.
  • the present invention provides an image acquisition process for acquiring an X-ray CT image of a measurement object on a three-dimensional coordinate axis, an actual measurement process for actually measuring the three-dimensional shape of the measurement object on the three-dimensional coordinate axis, and an image acquisition process.
  • a three-dimensional measurement method is provided.
  • the present invention provides an X-ray so that a computer converges a sinogram of an X-ray CT image of a measurement object acquired on a three-dimensional coordinate axis into a three-dimensional sinogram of the measurement object actually measured on the three-dimensional coordinate axis.
  • An X-ray three-dimensional image correction program for executing an image correction process for correcting a CT image is provided.
  • (A) and (b) are the side view and top view of the image reconstruction apparatus classified by X-ray energy which concern on embodiment of this invention. It is a figure for demonstrating the image reconstruction according to X-ray energy by this invention.
  • (A) (b) is a front view which shows an example of a detector, respectively. It is a figure which shows an example of a characteristic X-ray. It is a figure for demonstrating the dual energy method. It is a figure which shows an example of a line attenuation curve. It is a figure for demonstrating the successive approximation reconstruction method.
  • (A) is sectional drawing which shows another example of a detector
  • (b) is a front view which shows another example of a detector.
  • (A) and (b) are the front views and sectional views which show another example of a detector. It is a figure for demonstrating the energy separation by the filter in an example of FIG. It is a block diagram for demonstrating the functional structure of the X-ray three-dimensional measuring apparatus which concerns on embodiment of this invention. It is a side view of the X-ray three-dimensional measuring apparatus which concerns on embodiment of this invention. It is a top view of the X-ray three-dimensional measuring apparatus which concerns on embodiment of this invention. It is explanatory drawing for demonstrating the sinogram of the X-ray CT image of a measurement object. It is explanatory drawing for demonstrating the sinogram of the measurement data of the three-dimensional shape of a measuring object.
  • FIGS. 1A and 1B are diagrams showing an example of the configuration of an image reconstruction apparatus classified by X-ray energy according to an embodiment of the present invention, and FIG. 2 shows more specific X-ray energy by the apparatus. It is a figure explaining another image reconstruction.
  • the present invention in addition to the transmission amount change used in normal X-ray CT imaging, it is necessary to identify the species contained in the sample 2 to be imaged.
  • the characteristic X-rays generated when the X-rays from 1 are irradiated are detected by the energy dispersive detector 4, and information on the elements constituting the imaging target sample 2 and their concentrations are obtained from the energy peaks of the characteristic X-rays. To do.
  • the detector 4 having the energy dispersibility in the present invention can include a plurality of sub-detectors 40 arranged in a line shape or a panel shape as illustrated in FIGS. 3A and 3B. . It is desirable that the sub-detectors 40 have a structure that prevents the influence of scattered radiation by shielding them with a shielding material such as lead or tungsten.
  • each sub-detector 40 is capable of acquiring characteristic X-rays derived from each element obtained when X-rays are applied to the imaging target sample 2 composed of a plurality of elements as a radiation energy spectrum by photon counting. It is preferable to have.
  • detectors examples include semiconductor detectors such as cadmium telluride CdTe and zinc cadmium telluride CdZnTe, and scintillation detectors such as cesium iodide CsI and sodium iodide NaI.
  • the sub-detector 40 When the sub-detector 40 is arranged in a line shape (FIG. 3A), only one section is photographed while rotating the sample 2 arranged between the X-ray source 1 and the detector 4 by the drive mechanism 3. To do. A 3D image is acquired by stacking tomographic photographs by physically moving the sample table up and down for each cross-sectional image.
  • the drive mechanism 3 can rotate the sample stage on which the sample 2 is mounted by 360 degrees, and translate the X direction connecting the X-ray source 1 and the detector 4, the Y direction orthogonal thereto, and the up and down Z direction. .
  • a fluoroscopic image is acquired while rotating the sample 2 by the driving mechanism 3, and a three-dimensional image is acquired by reconstruction calculation.
  • a fluoroscopic image is acquired for each rotation angle of the sample 2, characteristic X-ray spectrum data for each pixel is acquired.
  • FIG. 4 shows a spectrum having peaks corresponding to aluminum Al and iron Fe.
  • FIG. 2 as an example of a more specific sample 2, a sample in which two kinds of metals of aluminum 21 and iron 22 are scattered in the resin 20 is illustrated, and X-rays are irradiated from the X-ray source 1 to the sample.
  • the characteristic X-rays generated in this manner are detected as a radiation energy spectrum by photocounting using the detector 4 such as the semiconductor detector or the scintillation detector described above.
  • the detected spectrum has respective peaks of aluminum and iron as in FIG.
  • the obtained characteristic X-ray peak is digitized by signal processing means (not shown).
  • the peak intensity of each of the aluminum 21 and iron 22 is quantified based on an energy threshold set in advance so that the aluminum 21 and iron 22 can be identified from the resin 20 in the sample 2, thereby obtaining an upper limit value.
  • a perspective image of only the aluminum 21 based on the spectral numerical data between the lower limit values and a perspective image of only the iron 21 based on the spectral numerical data larger than the upper limit value can be acquired.
  • a fluoroscopic image of the resin 20 is also acquired based on the spectral numerical data smaller than the lower limit value.
  • the obtained fluoroscopic image is reconstructed by an image reconstructing means (not shown), and reconstruction calculation for each energy is performed.
  • FIG. 6 shows an example of a wire attenuation coefficient curve of iron and aluminum when an 80 kV X-ray source and a 150 kV X-ray source 1b are used.
  • the sample has a complicated shape in which the X-ray passage distance varies greatly depending on the imaging direction as an artifact generation condition
  • the measured value and the assumed value are compared and corrected each time, and the correction is repeated until the measured value and the assumed value are within an allowable error range set in advance. Can be removed.
  • brute force method brute force search
  • greedy method hill climbing method
  • annealing method back propagation method
  • genetic algorithm genetic programming
  • evolution strategy evolution strategy
  • evolutionary programming etc.
  • Various algorithms can be used.
  • the signal processing means and the image reconstruction means are not shown here, but are constituted by hardware such as a computer and software such as a program mounted thereon.
  • a communication medium such as the Internet or a recording medium such as a USB
  • an arithmetic processing unit such as a CPU or a memory
  • Various processes are executed by a storage unit or the like.
  • Various data and result data necessary for this execution are appropriately input via an input unit and a communication unit, and output via an output unit and a display unit.
  • FIG. 8A and 8B show a detector having a configuration in which a semiconductor detector and a scintillation detector are combined as another embodiment of the energy dispersive detector according to the present invention.
  • a CdTe semiconductor detector that directly converts X-rays into electrons is provided on the X-ray incident side, and a scintillator that uses CsI that converts X-rays to light on the back side thereof.
  • a photodiode or a photomultiplier using a semiconductor such as Ge or Si that converts light into an electric signal is provided.
  • CdTe and CsI may be arranged in reverse, that is, an X-ray first enters CsI and passes through this to reach CdTe.
  • a semiconductor detector such as CdTe that can detect an electrical signal on one pixel and a scintillation detector such as CsI that can detect light are alternately arranged in a chessboard shape. It is installed. According to these configurations, energy separation and X-ray absorption values (CT values) can be acquired simultaneously, and the configuration of the entire apparatus can be simplified and downsized.
  • FIG. 9 (a) and 9 (b) show an embodiment of a detector that performs energy separation using a filter.
  • a metal filter 50 is provided in front of the CCD camera 5 as a detector (see FIG. 9B, not shown in FIG. 9A), and for each pixel as a countermeasure against scattered radiation.
  • a partition 51 is provided.
  • the sample showing high energy by cutting the energy region corresponding to the resin constituting the sample 2 (see FIG. 2), for example, with the metal filter 50 appropriately selected in advance. Only the constituent elements, in this example aluminum and iron, can be extracted. After the extraction, the reconstruction process described above is performed.
  • the X-ray three-dimensional measurement apparatus 10 includes an image acquisition unit 100 that acquires an X-ray CT image of the measurement object O on the three-dimensional coordinate axis, and a tertiary of the measurement object O on the three-dimensional coordinate axis.
  • the image acquisition means 100 irradiates the measurement object O with X-rays and detects projection data for each rotation angle of the measurement object O, whereby the X-ray CT of the measurement object O on a predetermined three-dimensional coordinate axis. Get an image.
  • the image acquisition unit 100 includes, for example, an X-ray source 101 that emits X-rays, a detector 102 that detects characteristic X-rays that have passed through the measurement object O, and an X-ray source 101 and a detector 102. Measured by the detector 103, the common stage 104 for installing the X-ray source 101, the detector 102 and the installation table 103, and the detector 103.
  • a signal processing unit 105 that digitizes the characteristic X-ray dose (characteristic X-ray peak) and an image reconstruction unit 106 that reconstructs an image based on numerical data obtained by the signal processing unit.
  • the installation base 103 is configured to perform a rotational motion around a predetermined rotational axis by a moving mechanism (not shown) and to perform a linear motion along an axis perpendicular to the rotational axis.
  • the installation table 103 is preferably made of granite or ductile cast iron having high rigidity.
  • the center of the three-dimensional coordinate axes (XYZ axes) used in the image acquisition unit 100 is the center position of the common stage 104 in a plan view and is a predetermined position from the upper surface of the common stage 104 as shown in FIGS. It is arranged at a position above the height.
  • the signal processing means 105 and the image reconstruction means 106 are configured by hardware such as a computer C and software such as programs installed therein. Specifically, when a program for the signal processing unit 105 and the image reconstruction unit 106 is read into the computer C via a communication medium such as the Internet or a recording medium such as a USB, an arithmetic processing unit such as a CPU or a memory Various processes are executed by a storage unit or the like. Various data and result data necessary for such execution are appropriately input via an input unit or a communication unit, and output via an output unit or a display unit (for example, display screen D).
  • a communication medium such as the Internet or a recording medium such as a USB
  • an arithmetic processing unit such as a CPU or a memory
  • Various processes are executed by a storage unit or the like.
  • Various data and result data necessary for such execution are appropriately input via an input unit or a communication unit, and output via an output unit or a display unit (for example, display screen D).
  • the image reconstruction unit 106 is a maximum likelihood estimation / expected value maximization reconstruction method (hereinafter referred to as “ML-EM reconstruction method”) in the successive approximation reconstruction method.
  • ML-EM reconstruction method a maximum likelihood estimation / expected value maximization reconstruction method
  • a linear scale may be arranged between the X-ray source 101 and the detector 102. If it does in this way, the position of the installation base 103 can be grasped
  • the actual measurement means 200 is a bridge-type device having a probe P as shown in FIGS. 12 and 13, and actually measures the three-dimensional shape of the measurement object O on a predetermined three-dimensional coordinate axis.
  • the three-dimensional coordinate axes used in the actual measurement unit 200 are the same as the three-dimensional coordinate axes used in the image acquisition unit 100.
  • the three-dimensional coordinate axis (the origin of the probe P) is set automatically or by an operator's operation so that the positional relationship of the probe P of the measurement object O, the image acquisition unit 100, and the actual measurement unit 200 coincides.
  • a setting method for example, using a gauge described in Japanese Patent Application Laid-Open No. 2012-137301, the center coordinates of the sphere on the X-ray CT image of the gauge and the gauge measured by the probe P of the actual measurement means 200 are used.
  • combine with the center coordinate of this sphere are mentioned, It is not limited to these.
  • the actual measurement means 200 has a moving mechanism 201 that moves the probe P relative to the measurement object O installed on the installation table 103.
  • the moving mechanism 201 is supported by a support member so that it can be moved up and down in the vertical direction, a cylindrical spindle having a probe P at the tip, a Z-direction drive mechanism for moving the spindle up and down, and the installation table 103 and the spindle in the vertical direction.
  • an X-direction drive mechanism and a Y-direction drive mechanism that move relative to each other in directions orthogonal to each other.
  • an air balance mechanism that generates a push-up force corresponding to the weight of the spindle including the probe P on the spindle can be employed as a part of the moving mechanism 201 or the actual measurement means 200.
  • the probe P and the moving mechanism 201 are installed on the common stage 104 on which the X-ray source 101, the detector 102, and the installation base 103 for the measurement object O described above are arranged. That is, elements for X-ray CT image capturing and elements for three-dimensional shape measurement are combined on one stage to constitute one measuring apparatus. The setting of the three-dimensional coordinate axis in this apparatus configuration is as described above.
  • the actual measurement means 200 includes an input unit 202 that can be operated by an operator, and also includes a probe moving unit 203 that moves the probe P in response to an operation input from the input unit 202. Further, a pressure-sensitive sensor S is provided at the tip of the probe P. When the probe P moved by the operator's input unit 202 through the probe moving means 203 comes into contact with the measurement object O, the pressure-sensitive sensor S detects the contact, and the three-dimensional information of the contacted position is obtained. It is to be detected. The detected three-dimensional position information of the measuring object O is sent to the computer C or the like for processing.
  • the probe moving unit 203 is also configured by hardware such as the computer C and software such as a program mounted on the computer C. When the program for the probe moving unit 203 is read into the computer C, the CPU or the like Various processes are executed by the arithmetic processing unit and a storage unit such as a memory.
  • the image correction means 300 corrects the X-ray CT image of the measurement object O acquired by the image acquisition means 100 with the three-dimensional shape of the measurement object O actually measured by the measurement means 200. As shown in FIG. 11, the image correction means 300 displays the X-ray CT image data acquired by the image acquisition means 100 and the three-dimensional shape data actually measured by the actual measurement means 200 as a sinogram on the display screen D.
  • the X-ray CT image is corrected by reconstructing the image using the ML-EM reconstruction method in the successive approximation reconstruction method so that the sinogram of the X-ray CT image converges to a sinogram having a three-dimensional shape.
  • Correction means 302 for performing the above operation.
  • the display unit 301 and the correction unit 302 are configured by hardware such as the computer C and software such as a program installed therein, and the program for the display unit 301 and the correction unit 302 is stored in the computer C.
  • various processes are executed by an arithmetic processing unit such as a CPU or a storage unit such as a memory.
  • FIG. 14 is an explanatory diagram for explaining a sinogram of an X-ray CT image of the measuring object O
  • FIG. 15 is an explanatory diagram for explaining a sinogram of actually measured data of the three-dimensional shape of the measuring object O. is there.
  • the sinogram is an image expressing a detection signal for each angle as a sin wave when the measurement object O is rotated 360 °, and is acquired for each cross section of the measurement object O.
  • a sinogram (CT sinogram) of an X-ray CT image in a predetermined cross section of the measurement object O having an elliptical shape in plan view acquired by the image acquisition unit 100 is expressed by an image as shown in FIG. 14, for example.
  • a sinogram (actually measured sinogram) of three-dimensionally measured data in a predetermined cross section of the measurement object O having a rectangular shape in plan view measured by the actual measuring means 200 is expressed by an image as shown in FIG. 15, for example.
  • Four sinograms A to D shown on the left side of FIG. 15 are sinograms respectively corresponding to the edges A to D of the measuring object O shown on the right side of FIG.
  • the edge of the measurement object O is a contact point between the pressure-sensitive sensor S of the probe P of the actual measurement means 200 and the measurement object O.
  • the ML-EM reconstruction method used for image correction will be described with reference to FIGS.
  • the ML-EM reconstruction method is a method of repeatedly calculating what kind of image the calculated projection data close to the measured projection data can be obtained.
  • projection data sinograms
  • the outer shape is expected to be an ellipse from the outermost sinogram shape.
  • the 90 ° and 270 ° sinograms suggest that a bright substance exists at the top of the ellipse and an air layer exists at the bottom.
  • An outline of the ML-EM reconstruction method is a method of constructing a cross-sectional image without contradiction by repeatedly performing such operations simultaneously.
  • FIG. 17 shows a comparison result between a cross-sectional image reconstructed using the ML-EM reconstruction method and a cross-sectional image reconstructed using the filter-corrected back projection method (hereinafter referred to as “FBP method”).
  • FBP method filter-corrected back projection method
  • the FBP method is processed by the blur correction filter at the time of reconstruction.
  • the edge is emphasized or the contrast is different due to the influence of the correction filter.
  • These problems cause measurement errors, and the measurement errors may increase depending on the shape of the measurement object.
  • the ML-EM reconstruction method can suppress the occurrence of artifacts manifested by the FBP method.
  • the ML-EM reconstruction method is a method for deriving a statistically most probable image based on projection data, (1) there is a possibility that the image will not converge due to a statistical method. (2) a reconstructed image
  • the inventor of the present invention takes a sinogram obtained from an accurate cross-sectional image created from data or CAD data actually measured by a three-dimensional measuring machine such as the actual measurement means 200 in the present embodiment, and converges to the sinogram. By correcting the whole as described above, the above problem of the ML-EM reconstruction method was solved.
  • FIG. 18 is an explanatory diagram for explaining a method of correcting an X-ray CT image using a sinogram (actual sinogram) of actually measured data having a three-dimensional shape.
  • the position of the probe P (pressure-sensitive sensor S) of the actual measurement means 200 can be expressed by a sin wave (sinogram), and the X-ray CT image acquired by the image acquisition means 100 can also be expressed by a sin wave (sinogram).
  • a sinogram (CT sinogram) of the X-ray CT image is obtained.
  • the X-ray three-dimensional measuring apparatus 10 has a vibration isolation function as a countermeasure against external vibration.
  • the X-ray three-dimensional measuring apparatus 10 is preferably shielded by a shield made of lead, tungsten, or the like, and it is preferable that the temperature and humidity inside the X-ray three-dimensional measuring apparatus 10 be maintained constant by air conditioning means. In this way, the influence of the external environment can be suppressed when acquiring image information or acquiring position information of a three-dimensional shape, and more accurate three-dimensional information can be obtained.
  • the X-ray source 101 of the image acquisition unit 100 irradiates the measurement object O with X-rays, and the projection data for each rotation angle of the measurement object O is detected by the detector 102, whereby predetermined three-dimensional.
  • An X-ray CT image of the measurement object O on the coordinate axis is acquired (image acquisition step: S1).
  • the acquired X-ray CT image sinogram (CT sinogram) of the measurement object O is displayed on the display screen D by the display means 301 as shown in FIG. 18 (CT sinogram display step: S2).
  • the three-dimensional shape of the measurement object O on the three-dimensional coordinate axis is actually measured by the actual measurement means 200 (measurement step: S3).
  • the actually measured three-dimensional sinogram (measured sinogram) of the measurement object O is displayed on the display screen D by the display means 301 as shown in FIG. 18, for example (measured sinogram display step: S4).
  • the actual measurement step S3 and the actual sinogram display step S4 may be performed before the image acquisition step S1 and the CT sinogram display step S2.
  • the X-ray CT image is corrected by reconstructing the image using the ML-EM reconstruction method so that the CT sinogram converges to the measured sinogram (image correction step: S5).
  • image correction step: S5 image correction step: S5
  • an image obtained by fusing the CT sinogram and the measured sinogram on the display unit 301 can be displayed on the display screen D to reconstruct the image.
  • an X-ray CT image of the measurement object O on a predetermined three-dimensional coordinate axis is used as an actual measurement value of the three-dimensional shape of the measurement object O on the same coordinate axis. Can be corrected.
  • the ML-EM reconstruction is performed so that the sinogram (actual sinogram) of the three-dimensional shape of the measuring object O actually measured by the actual measuring means 200 is regarded as a correct answer, and the sinogram (CT sinogram) of the X-ray CT image is converged to this correct answer. Since the X-ray CT image is corrected by realizing image reconstruction using the construction method, the time until convergence (reconstruction time) can be shortened.
  • the contact-type actual measurement means 200 using the probe P has been described.
  • a non-contact type actual measurement means using a laser, a CCD camera, or the like may be used.
  • an X-ray CT image is corrected using a sinogram (actual sinogram) of actual measurement data of the three-dimensional shape of the measurement object O
  • CAD data is used instead of the actual sinogram.
  • the X-ray CT image can also be corrected using a correct sinogram created using.
  • CAD data is subjected to voxel transformation and cross-sectional image transformation to create a correct sinogram, and image reconstruction using the ML-EM reconstruction method is realized so that the CT sinogram converges to the correct sinogram.
  • CT images can also be corrected.
  • the X-ray CT image of the measuring object comprised with a some substance Can be corrected by energy.
  • the X-ray CT image of the measuring object comprised with a some substance Can be corrected by energy.
  • FIG. 20 when a sample 2 in which two kinds of metals, aluminum 21 and iron 22, are scattered in a resin 20, is measured, first, the obtained characteristic X-ray peak is signaled. It is digitized by the processing means 105. At this time, the peak intensity of each of the aluminum 21 and the iron 22 is quantified based on an energy threshold that is set in advance so that the aluminum 21 and the iron 22 can be identified from the resin 20 in the sample 2.
  • a fluoroscopic image of only aluminum 21 based on the interstitial numerical value data and a fluoroscopic image of only iron 21 based on the spectral numerical data larger than the upper limit value are acquired. Further, a fluoroscopic image of the resin 20 is also acquired based on the spectral numerical data smaller than the lower limit value.
  • the image reconstructing means 106 reconstructs the obtained fluoroscopic images, acquires X-ray CT images for each energy, and obtains a CT sinogram. Thereafter, correct sinograms for each energy are created using CAD data, etc., and an image reconstruction using the ML-EM reconstruction method is performed so that the CT sinograms for each energy converge on these correct sinograms, The X-ray CT image is corrected for each energy.
  • each element provided in each embodiment and its arrangement, material, condition, shape, size, and the like are not limited to those illustrated, and can be appropriately changed.
  • each element with which each said embodiment is provided can be combined as much as technically possible, and the combination of these is also included in the scope of the present invention as long as the characteristics of the present invention are included.

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Abstract

L'invention concerne un dispositif et un procédé de reconstruction d'image à différentes énergies de rayons X par lesquels la reconstruction d'image peut être réalisée avec une précision accrue. Le dispositif de reconstruction d'image à différentes énergies de rayons X selon l'invention comprend : une source de rayons X (1) pour irradier aux rayons X un échantillon (2) dont il faut capturer l'image ; un détecteur de dispersion d'énergie (4) pour détecter les rayons X caractéristiques produits par l'échantillon (2) dont il faut capturer l'image ; un moyen de traitement de signal pour quantifier les crêtes des rayons X caractéristiques détectées par le détecteur (4) ; et un moyen de reconstruction d'image pour reconstruire les images sur la base des signaux du moyen de traitement de signal.
PCT/JP2014/064330 2013-05-29 2014-05-29 Dispositif et procédé de reconstruction d'image à différentes énergies de rayons x, et dispositif et procédé de mesure tridimensionnelle aux rayons x WO2014192889A1 (fr)

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EP14804436.5A EP3006924B1 (fr) 2013-05-29 2014-05-29 Dispositif et procédé de reconstruction d'image à différentes énergies de rayons x
JP2015519944A JP6280544B2 (ja) 2013-05-29 2014-05-29 Ｘ線エネルギー別画像再構成装置及び方法並びにｘ線三次元測定装置及び方法
US14/894,325 US9928619B2 (en) 2013-05-29 2014-05-29 Device and method for image reconstruction at different X-ray energies, and device and method for X-ray three-dimensional measurement
EP16180850.6A EP3109625B1 (fr) 2013-05-29 2014-05-29 Combinaison de données cao et de tomodensitométrie
US15/674,396 US10521936B2 (en) 2013-05-29 2017-08-10 Device and method for image reconstruction at different X-ray energies, and device and method for X-ray three-dimensional measurement

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2018059795A (ja) * 2016-10-05 2018-04-12 地方独立行政法人東京都立産業技術研究センター Ｘ線ｃｔ装置、画像補正方法及び画像補正プログラム
JP2018136946A (ja) * 2017-02-23 2018-08-30 公立大学法人首都大学東京 ３次元ｃａｄモデル部分検索方法及び３次元ｃａｄモデル検索方法
CN112393697A (zh) * 2020-11-09 2021-02-23 南京市计量监督检测院 一种无损测量医用鲁尔量规内尺寸的方法
WO2023007846A1 (fr) * 2021-07-27 2023-02-02 株式会社リガク Dispositif, système, procédé et programme de correction

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5922892B2 (ja) * 2011-08-26 2016-05-24 Ntn株式会社 転動体の検査方法および転動体の製造方法
JP6658552B2 (ja) * 2015-02-09 2020-03-04 株式会社ニコン Ｘ線計測装置の画像再構成方法、ｘ線計測装置の画像再構成プログラムおよびｘ線計測装置
EP3460388A1 (fr) * 2017-09-26 2019-03-27 Hexagon Metrology (Israel) Ltd. Positionnement global d'un capteur par rapport à différents carreaux pour une reconstruction de surface tridimensionnelle globale
CN109211945B (zh) * 2018-08-22 2021-03-19 东南大学 一种基于离散元分析沥青混合料空隙结构的方法
CN115264407B (zh) * 2022-06-14 2024-05-14 昆明理工大学 一种基于层析成像测量的管道智能成像检测器及检测方法

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH03108645A (ja) * 1989-09-22 1991-05-08 Yokogawa Electric Corp 組成断層分析装置
JPH11281747A (ja) 1998-03-27 1999-10-15 Toshiba Corp 放射線半導体検出器
US20050123089A1 (en) * 2003-12-09 2005-06-09 Man Bruno D. Method and apparatus for reduction of artifacts in computed tomography images
JP2006017714A (ja) * 2004-06-30 2006-01-19 General Electric Co <Ge> Ｃｔ計測を使用する境界推定のためのシステム及び方法
JP2006125960A (ja) 2004-10-28 2006-05-18 Hitachi Ltd 内部欠陥検査方法および装置
JP2006329917A (ja) 2005-05-30 2006-12-07 Hitachi Ltd 内部欠陥検査方法および内部欠陥検査装置
JP2008070219A (ja) 2006-09-14 2008-03-27 Hitachi Ltd Ｘ線ｃｔ装置
JP2009543603A (ja) * 2006-07-10 2009-12-10 コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ エネルギースペクトル再構成
JP2012137301A (ja) 2010-12-24 2012-07-19 Tokyo Metropolitan Industrial Technology Research Institute 三次元座標測定機簡易検査用ゲージ

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH07231888A (ja) 1994-02-22 1995-09-05 Toshiba Corp 放射線コンピュータ断層撮影装置
JP3455058B2 (ja) 1997-05-16 2003-10-06 株式会社東芝 冷蔵庫
US6533455B2 (en) 2000-08-31 2003-03-18 Siemens Aktiengesellschaft Method for determining a coordinate transformation for use in navigating an object
ATE371407T1 (de) 2002-07-12 2007-09-15 Mycrona Ges Fuer Innovative Me Verfahren und vorrichtung zur bestimmung der ist- position einer struktur eines untersuchungsobjektes
JP2004294287A (ja) 2003-03-27 2004-10-21 Toshiba Corp 非破壊検査装置
US7254209B2 (en) * 2003-11-17 2007-08-07 General Electric Company Iterative CT reconstruction method using multi-modal edge information
JP2005292047A (ja) 2004-04-02 2005-10-20 Sony Corp Ｘ線断層撮像装置及びｘ線断層撮像方法
US7840249B2 (en) 2004-11-24 2010-11-23 University Of Iowa Research Foundation Clinical micro-CT (CMCT) methods, techniques and apparatus
EP1933170A1 (fr) 2006-12-07 2008-06-18 Universiteit Gent Procédé et système de tomodensitométrie
JP5487519B2 (ja) 2009-12-10 2014-05-07 株式会社日立製作所 産業用ｘ線ｃｔ装置および撮像方法
JP5875790B2 (ja) * 2011-07-07 2016-03-02 株式会社東芝 光子計数型画像検出器、ｘ線診断装置、及びｘ線コンピュータ断層装置
US9237874B2 (en) 2012-04-30 2016-01-19 General Electric Company Method and system for non-invasive imaging of a target region

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH03108645A (ja) * 1989-09-22 1991-05-08 Yokogawa Electric Corp 組成断層分析装置
JPH11281747A (ja) 1998-03-27 1999-10-15 Toshiba Corp 放射線半導体検出器
US20050123089A1 (en) * 2003-12-09 2005-06-09 Man Bruno D. Method and apparatus for reduction of artifacts in computed tomography images
JP2006017714A (ja) * 2004-06-30 2006-01-19 General Electric Co <Ge> Ｃｔ計測を使用する境界推定のためのシステム及び方法
JP2006125960A (ja) 2004-10-28 2006-05-18 Hitachi Ltd 内部欠陥検査方法および装置
JP2006329917A (ja) 2005-05-30 2006-12-07 Hitachi Ltd 内部欠陥検査方法および内部欠陥検査装置
JP2009543603A (ja) * 2006-07-10 2009-12-10 コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ エネルギースペクトル再構成
JP2008070219A (ja) 2006-09-14 2008-03-27 Hitachi Ltd Ｘ線ｃｔ装置
JP2012137301A (ja) 2010-12-24 2012-07-19 Tokyo Metropolitan Industrial Technology Research Institute 三次元座標測定機簡易検査用ゲージ

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
See also references of EP3006924A4
SHIGEHITO SUZUKI: "Various Methods of Iterative Least-Squares Image Reconstruction for Emission Tomography", JAPANESE JOURNAL OF MEDICAL PHYSICS, vol. 19, no. 3, 30 September 1999 (1999-09-30), pages 193 - 204, XP055292067 *
TAKAHIRO NISHIHATA ET AL.: "Sinogram-based Beam Hardening Correction using Volume Conservation for Single-material Objects", 2012 NENDO SEIMITSU KOGAKUKAI SHUKI TAIKAI GAKUJUTSU KOENKAI KOEN RONBUNSHU, 1 September 2012 (2012-09-01), pages 273 - 274, XP008181552 *

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2018059795A (ja) * 2016-10-05 2018-04-12 地方独立行政法人東京都立産業技術研究センター Ｘ線ｃｔ装置、画像補正方法及び画像補正プログラム
JP2018136946A (ja) * 2017-02-23 2018-08-30 公立大学法人首都大学東京 ３次元ｃａｄモデル部分検索方法及び３次元ｃａｄモデル検索方法
JP7075654B2 (ja) 2017-02-23 2022-05-26 東京都公立大学法人 ３次元ｃａｄモデル部分検索方法及び３次元ｃａｄモデル検索方法
CN112393697A (zh) * 2020-11-09 2021-02-23 南京市计量监督检测院 一种无损测量医用鲁尔量规内尺寸的方法
CN112393697B (zh) * 2020-11-09 2022-06-07 南京市计量监督检测院 一种无损测量医用鲁尔量规内尺寸的方法
WO2023007846A1 (fr) * 2021-07-27 2023-02-02 株式会社リガク Dispositif, système, procédé et programme de correction

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EP3006924B1 (fr) 2019-09-11
US20160133032A1 (en) 2016-05-12
US9928619B2 (en) 2018-03-27
EP3006924A1 (fr) 2016-04-13
US10521936B2 (en) 2019-12-31
JP6280544B2 (ja) 2018-02-14
EP3006924A4 (fr) 2017-03-01

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